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HEATING VENTILATINC AIR CONDITIONING GUIDE 1940
Table 10. Heat Gain from Various Sources
. . Source
Btu Per Hour
Sensible J Latent j Total
Electric Healing Equipment
Electrical Equipment--Dry Heat- -No Evaporated Water___ __
Electric Oven--Baking. Electric Equipment--Hearing Water--Stewing. Boiling, etc--
Electric Lights and Appliances per Watt (Dry Heat)--------------Electric Lights and Appliances per Kilowatt (Dry Heat)---------Electric Motors per Horsepower... Electric Toasters or Electric Griddles.-------------------Coffee Urn--Large. IS in. Diameter--Single Drum Coffee Urn--Small. 12 in. Diameter--Single Drunu Coffee Urn--Approx. Connected Load per Gallon of CapacityElectric Range--Small Burner---------- ------------ ------------------ ---------
. Electric Range--Large Burner-------------------------------------- ----------- .. Electric Range--Oven.. Electric Range--Warming Compartment................... Steam Table--Per Square Foot of Top Surface------Plate Warmer--Per Cubic Foot of Volume-------------Baker's Oven--Per Cubic Foot of Volume-------------Frying Griddles--Per Square Foot of Top SurfaceHot Plates--Per Square Foot of Top Surface---------Hair Dryer in Beauty Parlor--600 w.,, Permanent Wave Machine in Beauty Parlor--24-25 w Units..
100%
80% 50%
3.4 3413
_ 2546 0% 2000 1200 600 .* *
8000 ` 1025
300 850 3200 * *
2050 2050
o% 20% 50%
0 0 0
10% 2000 1200
600 * *
2000 0 800
0 1300
* *
0 0
100% 100%
100% 3.4
3413 2546 100% 4000 2400
1200 3400
7500 10000
1025 1100
850 4500
4600 9000 2050 2050
Gas Burning Equipment
Gas Equipment--Dry Heat--No Water Evaporated----- .------------------------------------ 90%
Gas Heated Oven--Baking------------..........-------------------------.---------------------------------- 67%
Gas Equipment--Heating Water--Stewing, Boiling, etc--------------------------- ------- 50%
Stove. Domestic Type--No Water Evaporated--Per Medium Size Burner-------- 9000
Gas Heated Oven---Domestic Type-------------------------------------------------------- ----- 12000
Stove. Domestic Type--Hearing Water--Per Medium Size Burner-------------------Residence Gas Range--Giant Burner (About SH fa* Diameter)------------------------Residence Gas Range--Medium Burner (About 4 in. Diameter)-------------------Residence Gas Range--Double Oven (Total Size 18 in. x 18 in. x 22 in. High)-------
Residence Gas Range--Pilot-------------- ----------------------------------------------------- ----------Restaurant Range---4 Burners and Oven------------------------------------------------------------Cast-Iron Burner--Low Flame--Per Hole------- -------.----- ------------------ ---------
Cast-Iron Burner--High Flame--Per Hole...------- --------------------------------- ---........... Simmering Burner............ ------------------------ ---------------------------------------------------- *--
5000 * * *
* *
* *
Coffee Urn--Large. 18 in. Diameter--Single Drum....................... ............................. 5000
Coffee Urn--Small, 12 in. Diameter--Single Drum.--------------------- ----------------........ 3000
Coffee Urn--Per Gallon of Rated Capacity------------- --------------------- ------.............. 500
Egg Boiler--Per Egg Compartment.............................. --........... ..................--.....---: 2500
Steam Table or Serving Table--Per Square Foot of Top Surface-- --............... , 400
Dish Warmer--Per Square Foot of Shelf.------------------------*.......... ............. ........------- 540
Cigar Lighter--Continuous Flame Type........ ----------------........... :.............................. 2250
Curling Iron Heater.......... ...............--.............. ........................... ------------------ -----------
Bunsen Type Burner--Large--Natural Gas------ ------------------------------------------- ------
Bunsen Type Burner--Large--Artificial Gas........... ------------ ...-------------------- ------
Bunsen Type Burner--Small--Natural Gas.......................--......... ................ .............
Bunsen Type Burner--Small--Artificial Gas..................................... -........... -............
Welsbach Burner---Natural Gas-...... -------------- ------------------------- ------------ --------------
Welsbach Burner--Artificial Gas...... ......... .................................................... - ---------
Fish-tail Burner--Natural Gas...... ..................... ............................. ......-......................--
Fish-tail Burner--Artificial Gas........................... ........-----
------------.............
2250 * * \ * * * *
Lighting Fixture Outlet--Large, 3 Mantle 480 C-P------------------------------------------- 4500
Lighting Fixture Outlet--Small, 1 Mantle 160 C.P..--...................--.......... .............. 2250
One Cubic Foot of Natural Gas Generates----------------------------------------------------- ---- 900
One Cubic Foot of Artificial Gas Generates------------------------------ -------------------------- 540
One Cubic Foot of Producer Gas Generates--------------------------------------------------- -- 135
10% 33% 50% 1000 6000 5000
* * * * *' *
5000 3000
500 2500
900 60
250 250 * * * * *
0
0
0
500 250 100
60 15
100%
100%
100% 10000
18000 10000
12000
10000 18000
250
100000 100 250
2500
10000 6000
1000 5000
1300 600
2500
2500 5000
3000 3000
1800
3000
1800 5000
3000
5000 2500
1000
600
150
___________ Steam Healed Equipment
Steam Heated Surface Not Polished--Per Square Foot of Surface.-- Steam Heated Surface Polished--Per Square Foot of Surface-............ . Insulated Surface. Per Square Foot................................................. Bare Pipes. Not Polished Per Square Foot of Surface.------------Bare Pipes. Polished Per Square Foot of Surface.------------------Insulated Pipes. Per Square Foot....................... .............................. Coffee Urn--Large, 18 in. Diameter--Single Drum---------------------- ----Coffee Urn--Small, 12 in. Diameter--Single Drum--.............. -.......-- Egg Boiler--Per Egg Compartment.............--............... -........... -....... -- Steam Table--Per Square Foot of Top Surface..................... --................
330 130
80 400 220 110 2000 1200 2500 300
0 0 0 0 0
0 2000 1200 2500
800
330 130 80 400 220 no 4000
. 2400 5000 1100
Miscellaneous
Heat Liberated from Hot Water used direct and on towels per hour--Barber Shops
30 100
30 I 200 1
60 300
Per cent sensible and latent heat depends upon use of equipment; dry heat, baiting or boiling.
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CHAPTER 8. COOLING LOAD
Heat Emission of Appliances
Heat generating appliances which give off either sensible heat or both . sensible and latent heat in an air conditioned enclosure may be divided into three general classes of equipment or devices:
1. Electrical appliances. 2. Gas appliances. 3. Steam heating appliances.
In the first group may be found such devices as lights, motors, toasters, waffle irons, etc. The capacities of most electrical devices may be determined from the watt capacity indicated on their name plates. The Btu equivalent of heat generated per hour is determined by multi plying the watt capacity by 3.4 (one watthour is equivalent to 3.413 Btu).
The capacities of electric motors are usually expressed in terms of horsepower instead of watts. If the motor efficiency is known, the watts input may be calculated from the formula:
where
p = 746 (hp) n
P = motor'input, watts. hp = motor load, horsepower.
n = motor efficiency (expressed as a decimal).
''
When the motor efficiency is not known the heat equivalent of electrical input can be approximately determined by applying data given in Table 9.
Table 9. Heat Generated by Motors
Nameplate Rating Horsepower
Hto 3^ H to 3 3 to 20
Heat Gain in Btu per Hour per Horsepower
Connected Load in Same Room Connected Load Outside of Room
4250 3700 2950
1700 1150 400
In the second group belong such appliances as coffee urns, gas ranges, steam tables, broilers, hot plates, etc. For heat generating capacities of such appliances refer to Table 10.
Considerable judgment must be exercised in the use of data given in Table 10. Consideration must be given to time of day when appliances are used and the heat they contribute at time of peak load. Only those appliances in use at the time of the peak load need be considered. Con sideration must also be given to the way appliances are installed, whether products of combustion are vented to a flue, whether they escape into the space to be conditioned, or whether appliances are hooded allowing part of the heat to escape through a stack. There are no generally accepted data available on the effects of venting and shielding heating appliances but it is believed that when they are properly hooded with a positive fan exhaust system through the hood that 50 per cent of the heat will be
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